HD video from DSLRs

The Nikon D90 and the Canon EOS 5D Mark II (Canon's SLR names are way too convoluted) both shoot HD video in addition to serving as DSLRs.

But one problem of shooting HD video with a CMOS is that since there is no real shutter like on a motion picture camera, each "frame" is captured by simply capturing lots of images per second with that CMOS. If you read it 24 times a second, you get 24 frames.

But if the CMOS doesn't refresh fast enough and the camera moves while the CMOS is refreshing, the bottom of the CMOS might be reading part of the image from a different time than the top of the CMOS, and that rolling shutter produces a bad motion wobble or skew (what Jim Jannard calls "jelly movement") as in this sample video footage from the D90.

Here are some sample unmodified Quicktime movie files from the Canon EOS 5D Mark II. Suffice it to say no serious filmmaker will be throwing away a camcorder after purchasing either of these DSLRs (unless that child you're filming doesn't move much; what, little kids run around?).

I'm sure they're fine still cameras, though. So few people make large prints anymore, so digital SLR resolution has been sufficient for their primary purposes: web galleries, 4x6 prints.